In order to manufacture sheets having mushroom-shaped hooks, i.e. consisting of a strip made of thermoplastic material, from which mushroom-shaped fastening elements protrude, each consisting of a stem substantially perpendicular to the sheet and consisting of a head part which protrudes laterally from the stem all around said stem, it is already known in the prior art to extrude a thermoplastic material from an extruder to shape and convey a sheet, substantially in a form which hereinafter will be referred to as molten and which, without being liquid, is nevertheless not completely solid but is partially softened, between a pressing roller and a forming roller, the forming roller comprising cavities having a complementary stem shape, such that when the sheet is passed between the two rollers, after solidification of the material, a sheet is obtained at the outlet comprising substantially cylindrical or conical stems which are subsequently deformed by pressing and/or by heating the upper part to form a mushroom-shaped fastening head.
These fastening elements made from the sheet are intended to cooperate with loops of a loop part consisting, for example, of a looped (knitted or woven) fabric, in particular made on a three-bar loom comprising warp threads, weft threads and loop threads, or a non-woven fabric forming loops.
It is desirable to provide fastening elements which, when they cooperate with the loop parts, have the greatest possible tensile strength and/or peel strength.